Split out a chunk of the apps as "experimental" and not built by default.
Split out a chunk of the apps as "experimental" and not built by default.

These are reset-yaw, osvr_calibrate, and diagnose-rotation - they all
mess around with internals in OSVR to an advanced degree and thus are
broken by path tree changes for now.

OSVR/OSVR-Core,feilen/OSVR-Core,godbyk/OSVR-Core,d235j/OSVR-Core,godbyk/OSVR-Core,d235j/OSVR-Core,leemichaelRazer/OSVR-Core,OSVR/OSVR-Core,godbyk/OSVR-Core,leemichaelRazer/OSVR-Core,OSVR/OSVR-Core,feilen/OSVR-Core,godbyk/OSVR-Core,Armada651/OSVR-Core,OSVR/OSVR-Core,godbyk/OSVR-Core,feilen/OSVR-Core,godbyk/OSVR-Core,Armada651/OSVR-Core,Armada651/OSVR-Core,OSVR/OSVR-Core,d235j/OSVR-Core,feilen/OSVR-Core,Armada651/OSVR-Core,Armada651/OSVR-Core,leemichaelRazer/OSVR-Core,leemichaelRazer/OSVR-Core,d235j/OSVR-Core,d235j/OSVR-Core,leemichaelRazer/OSVR-Core,feilen/OSVR-Core,OSVR/OSVR-Core